Known plants of the Lamiaceae family consist of about 180 genera which in turn consist of about 3500 species and they are distributed in almost all areas of the world. Many of them contain essential oil components and give off fragrance and since ancient times, they have been used as valued plants in various parts of the world.
In Europe, plants of the Lamiaceae family are known as medicinal or perfume plants. Included among the plants of the Lamiaceae family are not only various species in the genus Mentha such as Japanese mint which contains menthol, Mentha piperita from which to make peppermint, and midori hakka which contains spearmint oil, but also lavender which is famous as perfume, rosemary from which to make rosemary oil, as well as edible flavors exemplified by sage, marjoram, savory, and thyme.
Shiso has also been used as medicine in China. In traditional Chinese medicine, leaves of Perilla frutescens var. crispa f. purpurea (red shiso) are typically called “soyoh” or “shisoyoh” and are formulated in hanghe-kohboku-toh or kohso-san. Mature fruits of red shiso are called “soshi” and used in the treatment of cough, asthma, constipation, etc.
Shiso (Perilla frutescens var. crispa) which is widely cultivated in Japan is held native to the mid-southern part of China and was brought into Japan in old times. Shiso is not only used as medicament in the applications of traditional Chinese medicine; having a distinctive fragrance that can be recognized from the whole plant body and presenting bright colors that can be used in pigmentation, shiso also finds use in wider applications, e.g., as condiments, eaten fresh, or as pickles. For example, young buds of shiso (called murame if it is red shiso and aome if it is green shiso, or Perilla frutescens var. crispa f. viridis) are used as garnishing to be served with sashimi or as condiments; catkins of shiso (hojiso) are used as garnishing to be served with sashimi or eaten as tempura; leaves of green shiso (ohba) are used as condiments or as garnishing to be served with tempura or sashimi; leaves of red shiso are used for pigmentation of umeboshi (pickled plum) and other pickles. They are also frequently served in everyday meals as shiso furikake (ready-made, shiso-flavored toppings to go with white rice).
Thus, the refreshing scent and bright colors of shiso have long been relished by Japanese people and it may well be said that shiso is one of the most common and popular ingredients in food (Non-Patent Documents 1 and 2).
This preference of Japanese people for shiso is recently expanding to affect alcoholic beverages (Patent Document 1). In particular, “Tantakatan” (product of GODO SHUSEI CO., LTD.) and many other brands of shiso Shochu (shiso-flavored Japanese distilled spirit) are getting increasingly popular among consumers. Umeshu (plum wine) is also becoming a trend these days and among its commercial products are the one that is made by soaking not only plum but also shiso in Shochu.
The fragrance of shiso which is familiar to Japanese people originates from perillaldehyde, a kind of terpenes in its stem and leaves, and is said to account for 55% of the essential oils in shiso.
Patent Document 1: Official Gazette of JP 2005-143503 A
Non-Patent Document 1: HEIBONSHA'S WORLD ENCYCLOPEDIA
Non-Patent Document 2: TBS Britannica's Encyclopaedia Britannica